EFFECT OF MELOIDOGYNE-GRAMINICOLA (NEMATODA) ON THE ESTABLISHMENT, GROWTH AND YIELD OF RICE CV IR36

Rice cv IR36 was severely damaged by the rice root knot nematode Meloidogyne graminicola in pot experiments representing upland conditions. A high initial population density (Pi) of 80 second stage juveniles (J2)/ml of soil caused seedling death at 10 days after sowing; 80 % of seedlings had died after 32 days. The relationship between yield and Pi is described by the equation Y = Ymin + (1-Ymin)z. P; where the relative minimum yield (Ymin) = 0.05 and the term z = 0.3. The low value of z is consistent with a rapid generation time and severe early damage. The fecundity of females was inversely related to Pi. © 1990 BRILL.